“We don’t need the money,” he said. “We have more money than we’ll need for a long time.”
The company has raised about $800 million in venture capital. The move of other companies, like LinkedIn, Groupon, and Zynga toward IPOs this year, has raised speculation that Twitter might also soon file to go public. But Costolo dismissed that idea.
“[The money we’ve raised] is going to allow us to scale the company the way we want to scale it,” Costolo said. “We don’t want to be beholden to an IPO window. I want the company to go public when the company is ready and prepared to be a public company, and not at the whim of some window.”
Costolo also said the service now has almost 250 million tweets per day, up from 100 million at the beginning of the year. About half of the company’s 100 million monthly active users are active every day, up from 30 percent at the beginning of the year.
Twitter’s integration with iOS 5, announced last week, also helped the service. Daily signups from iPhone users went up 300%, which Costolo attributed to the frictionless way Twitter was integrated in iOS 5.
“It went better than we even hoped it would,” he said.
In his on-stage conversation with Battelle, Costolo addressed a range of other topics, including advertising. He stressed that any new ad formats the company introduces will fit naturally with how people use the service today.
“The things we’ll do in advertising on Twitter are just amplifications of things people already do on Twitter organically,” he said.
That’s the case with Twitter’s current ad formats, he said. Promoted Tweets and Promoted Trends, for example, are just sponsored versions of things that already happen on Twitter.
“We are not going to throw something new into the platform that people haven’t already tried and don’t already like,” he said.
The key challenge for the company as it grows is to keep the service simple, Costolo said, even as Facebook and Google + add more and more features.
“We want to be part of the fabric of every communication in the world. We think we can reach every person on the planet. And we think the way to do that is to simplify,” Costolo said.